Long-term monitoring of marine turtle nests in northeastern Brazil

Abstract

This study monitored marine turtle nests in a region known as the Potiguar Basin, which stretches from the northern region of Rio Grande do Norte State (5°4’1.15” S, 36°4’36.41” W) to eastern Ceará State (4°38’48.28” S, 37°32’52.08” W) in Brazil. We collected data from January 2011 to December 2019 to identify species of sea turtles that spawn in the basin, to analyze the nesting spatial-temporal pattern and nests characteristics, and to record effects of environmental and anthropic factors on nests. A field team examined sea turtle tracks and nests signs. Turtle clutches were monitored daily until hatchings emerged from the nests. We monitored nests of hawksbill (Eretmochelys imbricata; n = 238) and olive Ridley turtles (Lepidochelys olivacea; n = 103). The nesting season for E. imbricata occurred between December and May and for L. olivacea from March to August. Hawksbills had clutch size, incubation time, number of unhatched eggs, and dead hatchlings higher than olive Ridley turtles; nevertheless, they presented lower hatching success. Precipitation between 0 and 22 mm and relative humidity (RH) higher than 69% increased the hatching success rate for E. imbricata; however, rainfall above 11 mm and RH 64% had the same effect for L. olivacea. Signs of egg theft and human presence (e.g. vehicle traffic and plastic residues on the beach) were recorded and are considered threats to nests. The results of our long-term monitoring study in the Potiguar Basin provide basis for the implementation of mitigation measures and adoption of management policies at nesting beaches in this Brazilian region.

Nesting Ecology of Lepidochelys olivacea in Lobito, Angola

“…It occurs during the same time frame (November–February), with occasional records in October and March. However, at higher latitudes, there is a shift in the nesting period: northeastern Brazil: March-August [ 44 ], Colombia: August-September [ 45 ], Australia: February-November [ 46 ], and India: December-April [ 16 ]. Despite all these locations falling within tropical zones, the selection of nesting sites by female turtles is influenced by a combination of variables encompassing temperature, meteorological conditions, physical attributes of the nesting beaches, the adjacent oceanic environment, tidal conditions, and patterns of temperature and surface currents [ 47 , 48 ].…”

Threats and Vulnerabilities for the Globally Distributed Olive Ridley (Lepidochelys olivacea) Sea Turtle: A Historical and Current Status Evaluation

“…Olive ridley turtles have a highly flexible migratory lifestyle and use a wide variety of habitats [ 18 ]. In the Pacific region, they spend most of their life in the oceanic zone, whereas Atlantic turtles are commonly found in neritic areas [ 15 , 16 , 17 ]. Between pelagic feeding and coastal breeding areas, olive ridleys traverse from a few to thousands of kilometres, depending on the ecological conditions of these sites [ 18 , 37 , 38 , 39 ].…”

“…However, the main arribada nesting areas are located on the Pacific coast of Mexico, in Costa Rica, and in northeast India [ 45 , 46 , 47 ]. There are also several beaches reported as olive ridley solitary nesting spots in these regions [ 25 , 48 ], as well as in the Central African Atlantic Coast [ 26 , 49 ], Australia [ 50 ], French Guiana and Brazil in the western Atlantic [ 17 , 39 ], South American Pacific [ 51 ], South and Southeast of Asia [ 52 ], and on most island groupings throughout the tropics [ 5 , 53 ].…”

“…Olive ridleys show a great behavioural plasticity across the world. They can migrate through oceanic waters and feed on surface fauna, or remain in shallow coastal waters where they feed on invertebrates [ 15 , 16 , 17 ]. The nomadic behaviour of many olive ridley turtle populations represent a successful biological strategy for the opportunistic search for prey, which is patchily distributed.…”

Aspectos Da Ciência Da Sustentabilidade No Projeto Parceiros Do Mar

“…Para exemplificar, há os impactos ambientais à fauna marinha em decorrência de atividades antrópicas. Tartarugas marinhas, peixes-bois-marinhos, aves marinhas e cetáceos (golfinhos e baleias) atualmente constituem espécies ameaçadas de extinção em razão de impactos como degradação de manguezais, poluição e contaminação dos oceanos, condutas inadequadas na atividade pesqueira, atividade sísmica, exploração de gás e petróleo, colisão com embarcações, entre outros (6)(7)(8)(9)(10)(11)(12)(13)(14)(15) .…”